Semiconductor memories are used in many electronic systems to store data that may be retrieved at a later time. As the demand has increased for electronic systems to be faster, have greater computing ability, and consume less power semiconductor memories that may be accessed faster, store more data, and use less power have been continually developed to meet the changing needs. Part of the development includes creating new specifications for controlling and accessing semiconductor memories, with the changes in the specifications from one generation to the next directed to improving performance of the memories in the electronic systems.
Semiconductor memories are generally controlled by providing the memories with command signals, address signals, clock signals. The various signals may be provided by a memory controller, for example. The command signals may control the semiconductor memories to perform various memory operations, for example, a read operation to retrieve data from a memory, and a write operation to store data to the memory. The data may be provided between the controller and memories with known timing relative to receipt of an associated command by the memory. The known timing is typically defined by latency information. The latency information may be defined by numbers of clock cycles of system clock signals CK and CKF. The memories may be provided with system clock signals that are used for timing command signals and address signals, for example, and further provided with data clock signals that are used for timing read data provided by the memory and for timing write data provided to the memory. The memories may also provide clock signals to the controller for timing the provision of data provided to the controller.
Generation of internal signals by the memories, such as internal clock signals, consume power. In electronic systems where low power consumption is a priority, memory designs that reduce power consumption, for example, power consumed when generating internal signals, maybe desirable.